Anorexia Isn’t Just a Psychiatric Disorder

[♪ INTRO] Anorexia nervosa is a common and dangerous
illness that affects millions of people. For a long time, it’s been thought of primarily
as a psychiatric disorder, but new research published this week in the
journal Nature Genetics suggests there’s an important physiological
aspect as well. This research links the disorder to genetics
and metabolism, and it might change the way we understand
the origins of the illness as well as potential treatments. Anorexia nervosa is an eating disorder. Affected people may be dangerously underweight, with a restricted intake of food, and often also have a distorted body image. The end result is that the body is starved
of sufficient nutrients, which can lead to various medical complications
and even death. In fact, according to the U.S. National Institute
of Mental Health, anorexia is the most deadly mental disorder. Even with treatment, many patients struggle
to fully overcome anorexia. The authors of this new research suggest that
current treatments might be too focused on psychology, and fail to consider the physiology involved
in the disorder. This study pulled together genetic data on
almost 17,000 cases of anorexia nervosa among people
of European ancestry. When they compared that dataset with a control
group, they found 8 genetic variants significantly
associated with anorexia. Interestingly, some of these genetic traits
are also known to be related to levels of physical activity,
as well as to metabolism, the processes inside the body that convert
sustenance into energy. People suffering from anorexia have been known
to show signs of abnormal metabolism, but this has often
been thought of as a side effect of being starved of nutrients. However, the researchers say this genetic
link means that an unusual metabolism might actually
be partly responsible for causing the disorder. The researchers say we should think of anorexia
nervosa as arising from a combination of both psychological
and physiological factors. They say their analysis potentially expands
the list of risk factors for the disorder — that is, characteristics
that increase a person’s likelihood of developing it. And that in turn opens up a whole new avenue
for medical professionals looking to develop treatments for this deadly
disease. And anorexia isn’t the only illness that’s
more complicated than it seems. Another new study this week, published in the Journal of the American Medical Association, found a similar duality with dementia — but
the other way around. Dementia is defined as a decline in mental
ability that’s severe enough to interfere with a
person’s daily life. It can take many forms, but the most common
is Alzheimer’s disease, which affects more than five million people
in the US alone. And Alzheimer’s is known to be linked to
genes. There are well-known genetic risk factors
that are associated with a patient’s likelihood of
developing Alzheimer’s. But this new study found that dementia can
also be influenced by how healthy a person’s lifestyle
is. Like the first study, this one looked at a
wide sample of genetic data, this time from nearly 200,000 people in the
UK, including more than 1700 recorded cases of
dementia. The researchers assembled a genetic risk score
for each person, but also a lifestyle health score based on
each person’s self-reported diet, level of physical activity, and frequency
of smoking or drinking alcohol. They found that, even among people with a
high genetic risk, the incidence of dementia was significantly
lower in people with a healthier lifestyle versus people living less
healthy. The difference was small but noteworthy. Of the study participants with high genetic
risk of dementia, the disease developed in 1.78% of those with
unhealthy habits, but only 1.13% of those with a healthier lifestyle. In absolute terms, this would mean that if
people at high genetic risk improved their lifestyle, one case of dementia
could be prevented for each 121 at-risk individuals every decade. So this is certainly not a cure, but it does
seem that dementia, like anorexia nervosa, is related to a combination
of factors, both genetic and behavioral. Which is exciting because as we learn more, we might discover ways for people to offset
their built-in risk of dementia by adjusting their behavior and
lifestyle. But there’s definitely still more to be
learned. Both of these studies looked at specific populations
of people, mainly those of European ancestry. And it will no doubt take more study in more
diverse populations to tease out exact interrelationships between
the various factors involved in these diseases. But the takeaway here is that illness is complicated
– especially the ones we haven’t figured out
how to treat yet. Genetics can be very helpful in understanding
where diseases arise, but your genes are not your destiny. Diseases often have complex and interrelated
causes, and the more we come to understand that complexity, the better chance we have in the fight against
them. Thanks for watching this episode of SciShow
News. If you’re interested in helping us bring
great videos to the world every day, from news to quick questions to deep dives,
you can support us on Patreon. Check it out – patreon.com/scishow – that’s
the whole reason we can do this. Thanks everybody. [♪ OUTRO]

Many US citizens now at physical exam: Oh, so I can be someone potentially affected by anorexia, so doctor , keeping my 300 pounds is actually a lifestyle that protects me. So farewell these diets and exercises you are enforcing me, I won't be a candidate for anorexia. Bye…

I have some questions maybe someone can help me answer. I read some of the sources in the description, but couldn't find an answer.

I was under the impression that genes can be "turned on" and "turned off" in response to certain conditions the body is in (learned this in the veritasium video about anti-dandruff shampoo). So my question is: how do we know that these genetic associations with anorexia are really part of the cause and not just a response of the body to anorexia?

From the articles in the description I could not get an answer for this. They stated that they compared people who already have Anorexia Nervosa (defined by another source from the description as already showing symptoms of weight-loss or fail to gain weight when they are supposed to) to people who don't. In order to confirm that the genes are responsible, I would imagine they should also test people who recovered from anorexia to see if the genetic markers are still present. Else this could still just be an association, but not a causation.

DNA is stupid specific, its molecules wide and 2M LONG!!! Just think about that and how often your body does it. What was I talking about? Oh yea, so 8 genes out of 100,000+ that we only had 24,000, 6 years ago.

The general disclaimer was not enough in this. I'm generally for SciShows attempts at outlandish theory because it usually doesn't affect people, but here it does. The risk of developing alzeimhers based on active, healthy lifestyle was almost identical statistically, and those genetic markers for metabolism make explain everything or nothing, nor provide adequate detail on treatments that could target specific metabolic or diet changes that would reinforce the hypothesis. This is PopSci news, not SciShow news, and I've learned to expect more from SciShow

A friend of mine died last May from anorexia, after suffering for 8 years. Throughout all these years, she was continually shamed for her condition, both by her family and the staff of the hospital she was regularly admitted to. I feel like if they were a bit more understanding and didn't put so much pressure on her, she might have still been alive.

hey thanks for the sources. but could you maybe give a title to the sources. so i know which sources i need to click to get what? 🙂i was looking for the study on annorexia but the one source is just a general article about diagnosis it seems?

Question: if anorexia is now being shown as having a genetic and metabolic component, will there be less attacks (not by this community but in general) against people with obesity, as it can also have a genetic and metabolic component?

Fat shaming is the last acceptable form of discrimination it seems, which can lead to death just like anorexia. But it has always seemed like people suffering with anorexia get more sympathy than people suffering with obesity.

I do not want to take away from anyone's struggle. I simply would love people to treat all weight issues with compassion, rather than treating one with compassion and one with derision. Maybe then we all can find ways to be healthy instead of helping one side and shaming the other.

Anyone suffering with an ED please be aware that this video could be triggering. I know some people find this new information a relief, but for me I am taking it very hard. I am in recovery from anorexia nervosa and am finding this triggering.

what an incredible, groundbreaking find, for mental disorders to be affected by genetics? who woulve thunk! /sarcasmwell, i suppose this might be unexpected for blank slate/evolution stops at the neck believers, also no, genetics is your destiny

“Your genes are not your destiny” – Hank Green“You can only fight your genes for so long. You must accept the inevitable.” – my doctor. The moral is, my doctor was right. Fighting my genes only bought me two painful hellish years. Accepting the inevitable brought me inner peace. Twenty-five years later, through acceptance, I finally healed the damage caused by those two years of trying to fight the inevitable (healthy diet and exercise were NOT the answer – just a band-aid).

A study based on each persons self reported diet and level of physical activity etc is hardly scientific.Linking an eating disorder to genetics would probably endanger more lives than saving them. I can already see obese and body positivity moment types using this as food for the shape they are in.

I still think we are in the absolute infancy of understanding any mental health problems. We will look back on this point in history and see ourselves as blind men splashing around in the dark. (Speaking as someone who has suffered for 30 years and had every treatment available with only the most minor or temporary effects).

There is also research showing the impact of omega 3 and b vitamins on mental health. They have also found that pro inflammatory diets can trigger depression. This is why diet in mental health treatment should be included in the treatment plan with equal importance. It's not all about weight gain through any means, it should be about healthy weight gain consuming foods that promote good mental health

What did the difference look like, what was the power of the significance. Big Data can make anything look significant, but the power behind that significance is more important than the significance by itself. Significance plus low-power equals useless result. Genes, in any case have never been shown to reliably code for any behaviour in humans. Even the "most genetic psychiatric disorders" liks schizophrenia only occur by chance given one twin is diagnosed in a twin study (50% is chance…just sayin).

These kinds of studies attempting to relate behaviour to gene encoding are a yellow brick road to normativity hiding as the wizard of enlightenment. Genes code for RNA (FULL STOP). There are way to many steps between Genes and cognition to be able to reduce any behaviour to any variant, in addition there is little evidence to support the thesis that such eating conditions were prevalent anywhere before magazines like GQ and a vast supply of evidence that shows it to be culture-bound with mass-media exposure. That said, probably all psychiatric characterisations should be considered culter-bound.

Whoever is crunching your numbers and looking at this stuff with a critical eye is doing a generally ok job, but they arre behind the times with some of psychiatry BS. This study is so 90s…

In my psych classes nearly a decade ago, it was understood that basically every major mental illness is caused by an interaction between genes and environment (including behavioral factors). Was the medical field not in agreement?

for decades now, i have had trouble maintaining a proper weight. No matter how much i eat, i am always at least 10 lbs underweight, if not more. I at first attributed this to a high metabolism, but sometimes find that implausible as i can go as much as 15-30lbs under weight. I do not believe that this is psychological, as i think i am underweight, but back to the intial question. How does one find out if they have it?

I'm a bit skepticalEvery time there's a study that tries to show that a psychiatric disease has a genetic basis.Another study or review comes out that shows the results are negligible.This has been going on with schizophrenia for decades.I'm not that these conditions don't have a genetic component, everything does to a degree.I'm just skeptical about how much the research is gonna hold up after examinations and in future replications.But then I'll need to see the data and methodology first.

I’ve always thought there was also a metabolic part of anorexia but to undermine the psychological problems they have like thinking they eat too much, fear of food, or seeing their body improperly then…I’d say that’s underestimating the weight of the psychological part of it but I have also seen people who have had anorexia eat high amounts of food and their weight stay the same where others would gain so that’s always been a no brainer to me.

So media has no effect on causing anorexia in teenagers? I find that very hard to believe. The media burns an imagine into our children's mind at "how" the perfect woman/man should look. They can never reach these goals because they're unobtainable by a mere human. Hence anorexia is born. If you remove all media anorexia will as a disease disappear along with it.

I used to do in home computer repair in Naples and Marco Island FL. The vast majority of my clients were retired with many 80+. And in striking up conversations with them while running scans and such I found a very strong correlation about someone "being normal" and keeping physically active, socially active, mentally active, and spiritually active. By normal I mean they can carry on a normal conversation, remember past and recent events, get around ok, and have a minimal amount of achs. Sample size of about 300, mix of male/female married/unmarried with some only observations and others I politely asked why are they as capable as me yet many others their age arent. So get up and go see your friends at the church puzzle group lol.

Currently in tears. I have been trying to get help for the genetic factors of my anorexia for over a decade. I don't have the "proper" physiological symptoms and thus have never been able to receive treatment. I am working to take a dietary protocol I invented and used to heal my husband's Junior Idiopathic Arthritis and rework it to help with illness on a genetic level. Difficult to do, but not impossible. Thank you Hank and SciShow for this video.

As a recovered Anorexic I must admit what he’s saying about a wonky metabolism very might well be why I became Anorexic to begin with. Prior to Anorexia I never felt hunger. In order to feel hunger I starved in order to eat…later on that habit just lead to not eating at all because being Anorexic is “easy” when hunger is naturally rarely felt. Now that I’m better I’m right back to when I was younger…I seldom feel hunger or the need to eat…even drink…there is like no on switch for me unless I’m famished.

My metabolics lecturer strongly believed that their is a metabolic link and he have witnessed several cases where patients with fructosemia were also anorexic. Once they cut fructose out of their diets their body weight increased. (might have been galactosemia)

well, depression usually is the cause of everything. For example I could be the healthiest man on the planet since I'm vegan, non smoker, no kids, bicycle and fresh air …. but I am too depressed to actually feel good.If you're sad you're sad. Period.

Hey thanks for presenting anorexia in a non-triggering way. I'm two years into treatment and I can't tell you how poorly some handle the subject. People often overlook how it is a serious physical/medical issue it is, and it really affects our lives and health. Thanks for taking the medical stuff seriously.